Impulse remote control system



y 1952 F. H. OSBORNE ETAL 2,604,531

IMPULSE REMOTE CONTROL. SYSTEM Filed Dec. 21, 1946 5 Sheets-Sheet 1 TO LONG PULSE SEGMENT 0F SELECTOR INVENTORS- Rip 0550mm.

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3 Sheets-Sheet 2 F. H. OSBORNE ET AL IMPULSE REMOTE CONTROL SYSTEM July 22, 1952 Filed Dec.

INVENTORS. fxzp h. 0530mm: Ja/sw )Fxges.

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J: TIMING mar courncrrmmunlq M I 3 A i=- KELERSE LBTCH RELIY l I STEPPEK COIL y 1952 F. H. OSBORNE ETAL 2,604,531

IMPULSE REMOTE CONTROL SYSTEM Filed Dec. 21, 1946 s Sheets-sheaf. s

courncr TERnmnLs Patented July 22, 1952 2 ,604,531 V g IMPULSEREMOTE CONTROL SYSTEM Fred. H. Oshorne, Snyder, and-John H.- Riggs, Kenmore, N. Y.,.- assignors to The Rudolph Wurlitzer Company, Chicago, 111., a corporation Application December 21, 1946; SerialNo. 711,716 v 7 o'f'operations. in response to the signal.

The embodiment of the. present invention, selected. for illustration only, in common. with. that of the aforesaid patent, contemplates the 1 transmission. of signals fromthe transmitter to the receiver over. the power lines supplying power to the same. The signals herein are in theform of 'high frequency continuous discharge which is interrupted at the wall box transmitter to supply pulsed.si'gnals otherwise unmodulated to the receiyer. To this extent the efiective signal system iherein differs from theaforesaid patented system for that provides a continuous signal that is modulated by a secondsignal of. pulsed charactr'andof-hw frequency. Herein only a. pulsed high frequencysignal isutilized; V

One object of .the. present invention isto prevent operation at all times of the receiver by signals originating outside of the system.

Another object of the present invention is to providea simplified means of tuning one or more transmitters. simultaneously to which the single common receiver has been previously fixed tuned. rnifurther object of the inventionis to provide a stable frequency of transmission.

. One feature of the present inventionresides'in preventing extraneous signal operation. while the receiver is stancling by (shown in said patent) as well as. preventing extraneous signal operation .of the receiver'while it'isireceiving a wanted .or de sired signal to the end that the latter only is .ef-v

festive uponthe-receiver for theselection. desired. Ixtoth'er' words, alfalse or erroneoussignal will not be iimp'ose'd upon the receiver for selection purposes Thus the receiver herein at all times is essentially i-n'sensitiveito extraneous transients of a duration shorter than the coiied high'frequ'ency pulses imposed on the alternatinglcurrentsupply linei i msecond 'sfeature of the present invention re side's-in thetuning of the transmitter or transmitterswithoutthe necessity of utilizing meters and bymeans of a comparatively inexpensive tube installed'lnithe common receiver so that it may bepermanentlyincluded in the system for comparison useparticularly when crystal substitu tions are contemplated for repair purposes.

' s claims. (on. 117-353) A. third feature of the present invention consists inprovidinga simple and inexpensive means,- such as a quartz crystal trequency control -unit.,. in the-oscillator of the transmittal, for 'maimtaining a constant and staple frequency at the.

transmitten, I

Asupplementary feature resides in theinclusion. of 'a multiple position switch or multiple: switch =means for selectively associating the ap propriate capacity for one of a, selected group: of crystal frequencies so that the necessity for, trimmining at other than the selected crystal frequency is eliminated. a p v y Other. objects: and. features of the invention. will be. setforth more fully hereinafte The full nature of the invention will be undea stood from the accompanying drawings andthe following description and claims.

lntthe: drawings, v Fig. lis a, diagram showing. conventional form, the impulse transmitter portion of the systems; 7

Fig.2 is adiagram impulse receiver;. v v

; Fig.:.3=is a. diagramJ-i-n conventional. form oithee impulse stepper.

Fig.14sisa view of thepower transformer assoiciated with the stepper mechanism and a view thereof including the latch. release. and time delaystruoture associated therewith.

In common with the disclosurelof the aforesaid Patent N02.,3l87;444;dated October 2'5, l .9l5, the: present invention contemplates theinclusion of a high. frequency continuous carrienproduced by any wall box upon. coin deposition and modulated'by coded interruptions, the latter being derived. from an impulse generator which-may, iffdesire'd, Fbe of the. general type illustratedin the lower portion of Fig. Z-olfsaidpa-tent. a

Sucha'generatormodulates onmodifies a high frequencyc'arrier .wave as by imparting ;t ereto a long .pulseand. one ormore :short pulses n accordance with a predetermined code; up to the: number of possible selectionsdesired; i 1

"Much of the general description. of the',,fOT&-.= going patent applies to the present invention inqconventi'onal form f the wherefore same. isomitted for brevity, althoughv th .:said' patent'is formally :made .a part hereof only :i-nsofar 'as same :is not in conflict With:.that

which follows herein. .T-his conflict broadly zis" 7 such as a wall box and from long pulse segments 882| and contact blade 29.

Herein, see Fig. 1, line corresponds to the.

former, line 2| to the latter, although obviously as between ring 90 of said patent and selectorfirst contact, it is relatively immaterial which is connected for output purposes, so long as the recelver actuated impulse stepper ingly wired.

In Fig. 1 herein, 22 and 23 designate power supply lines connected to transformer 24having secondaries connected to certain terminals'of an eleven pole socket 25, with which is detachably associated an eleven pole plug 26; Taps 21 and 28'from the power lines connect to the socket and arecontrolled by switch 29 which may be of manual or coin actuated type and corresponds to switch-23 of said patent.

Lines 21 and 28 through the plugand socket connect to rectifier tube 30 6x5 GT/G type) supplying (D. C.) B voltage to the carrier wave generating system. Saidlines 21 and 28 also constitute an outlet for coupling coil 3|. to the alternating current line.

The high frequency carrier wave. generating system includes choke 32, resistance 33, quartz crystal 3B, oscillator tube (6V6 GT/G type) or the equivalent, multiple position switch 36, capacities 31a, 31b and 310, trimmer condenser 38 and inductance 39.

Switch 36 has lobe 36a associated selectively with contacts 31cc, 312)!) and/or 31cc, as desired or'required, to attain the peaked condition aforesaid. This, as statedjeliminates the necessity for trimming for crystals of other frequencies.

When lobe 36a engages contacts 31% and 3100 obviously capacities 31b and 310 are in multime and in the tank circuit. When: lobe 36a engages contacts 3111a, NM) and 3100, the capacities 31a, 31b and 310. are in multiple in the tank circuit. When lobe 36a engages only contact 3'lcc the capacity 310 only is in the tank circuit. Thus three different values of capacity can be selectively included in the tank circuit for the-crystal selected for use in the oscillator therebyproducing an arrangement that permits trimming to-peak performance by the trimming co'ndenser 38, since the crystal oscillates on only one frequency. Trimmingis effected for any one crystal of predetermined frequency characteristic and preferablythe' crystal is that used when lobe 36a connects capacitiesiilb and 310 in multiple. The circuit hereinillustrated thus is capable of keeping the primary of the oscillator tank coil peaked even though the frequency is shifted by inter-changing crystals and using therewith the multiple position switch 36 aforesaid. The circuit herein:illustrated is of regenerative charactor. Y

The'foregoing provides a means for maintaining a constant and stable frequency at the 'trans-' mitter of the remote control system. Thereceiver included indicator indicates. that the proper crystal has been used with the proper capacity and peakperformance is provided. This invention also, obviates the necessity of carrying around a signal generator to tune thevarious transmitters, i. e., several wall boxes-in an estabis correspond 4 lishment, to a common and the selected frequency, for each wall box would have thereon, for the servicemans convenience, the multiple switch 36 aforesaid and obviously crystal units can be calibrated and like units commonly designated and utilized.

It is furthermore noted that not'only are signal generators expensive, heavyand not very rugged, but portable types have a serious frequency drift and such generator requires the use Y of a skilled technician and for a considerable the receiver is illustrated. is illustrated a 12 pole socket 40, and lines 4| and 42 therefrom represent the signal input to the period, all of which is unnecessary with'the present invention.

Reference will now be had to Fig. 2 wherein In this figure there receiver, said lines being connected to the power supply lines to which the receiver and transmitters are connected. Lines 4| and 42 are suitably connected to the house wiring through the stepper (see Fig. 3) to which reference will be had more fully hereinafter. This receiver circuit also obtains voltage for filaments and rectifier from the power transformer, the primary connections being shownin Fig. 3 aforesaid.

In Fig. 2, 43, 44, 45, and 46 designate radio frequency transformer windings, 4! a radio frequency amplifier tube (65K? type), 48,,49, and

50 designate radio frequency interstage transformer windings, and 5! a duo-diode-triode (686)? type) tube.

The system includes a dual triode tube 52 (GSN'ZGT type) directly connected to the normally open relay 55 and the aforesaid tube 5| and is normally at plate current cutoff. A A tun-- ing eye tube 53. (6U5/6G5 type) is connected'as shown. Also illustrated in Fig. 2 is tube 54. The normally open relay 55 is closable only when a wanted ordesired signal is supplied thereto.

The present invention incorporates the application of, a negative voltage, developed by the amplified signals, backgupon the control grid of the remote cutoff tube. .The effect of the negative voltage on the control grid of the tube 41 is to reduce sensitivity, that is, the gain of the tube. Through appropriate resistance and capacity there is introduced a time constant in the negative voltage. This maintains the negative voltage upon the systembetweenpulses. Ac-

cordingly extraneous transients will not produce an extra action of the'selecting switch, shown in Fig. 3, nor cause it to hold over, thereby producing a wrong selection.

The separate secondaries of the interstage transformer develope an A. V. C. voltage and develope signaling voltage for operating the relay 55 associated with the selecting, switch shown in Fig.

Hence, there herein is a separation of function which is not present in said patent, which patent only provides protection against false signaling from transients when the receiver isstanding by, so that herein complete protection against transients at all times is maintained to prevent false signalling thereby- For a better understanding of the separation of functions reference will now be had to Fig. 2 wherein the receiver circuit grid G of the radio frequency amplifier tube 47 is connected. to ground through coils '45 and .45 and through resistors L and M, all in series. If no current is.

is eifectively;

caterer *rhecetiibden'tf'theiaferesaid tct netted-t6 eiouaeithrough t e resis an; iintI of; the plate current. potential diffe'r'hc'e' between V V catnaae H, the grid arcing negative tocaththefvbeurrrcffi input lines 4'1 aud t: sai signal is'a 'plifie'd at radio frequency and iassedto'the dudyuicde triode tube 5! through: the windings 45', Hand W or the interstaget ari's'fo'riner (not numbered). "rue signal undergoes three sees;

and serves 1 of ruse 5| coil 5:91 m the resistor return; ifig'to catho e E burst ground; connection at X. The an-sedan or the said unidirectional currn' upward through theres'istor M so that the'po'tential of the upper end of the re sistor M is"'rfeg'ative with, respect to ground, and the negarive potential tliusobtained is applied to grid G of the aforesaid tube}? through the filter resis mgr. 'aiic'the dons/re an at; all'in series. he; err-ear of such negative potential is to increase th negative; bias of the, grid '(GVI The result, the fore, of a-s gnarer properdurationwould bftddecrease the' s'ensitivityYof the tu e in to I sue a-si na asd aiso pe d creas t e sensitivity ub'ejfl' to s gna s of short duration, such t astrahsients; In actual use this results'dn the receiver sensitivity being maintained at a point atWhiohf it wanted; signals-- of proper duration but discrirninate against transients. The described condition of insensitivity to transient signals of tube-41. is obtained both during thewanted signal pulses and during the intervals between the wanteuisignai pulses; I

It is also, obvious that b proper choice or the verse of the" resistor K, relative .to the potentials developed across the resistor M, the sensitivity of the whole systn'i' may The effectively controlled. 7 Thus if the grid G of tube 41 is biased (inthe absence of signals) to a. point of reduced sensitivity, onlys'trong signal'slwillbe effective in producing the chain of events above described, and the relative vane of suen trong signals was respect to the strength ofany expected transients maybe preaeterimaed." p

(b) A second effect of the signal received by thetu'b' froin the tube 4'! is to produce a secolifid unidirectional current from diode iblate D through coil 19' and the'rsistorsB and (1 all in series, returning to" the cathode E through groundmnhectfin at X, and" prtaucmg a potential drop across the resistors Band C. A portiori of this potential is" applied to the g'ridA of tube 5| frdrfi the junction of' said res tors B and Cf The are resistors B C are jointly by-passed by the condenser E, which effectively short circuits the said two resistors 'for signals of short duration, such as transients. In like 'fashion the resistor C is separately Icy-passed v respect to the value of resistor C alone.

Thus, if any transient signal has not been sufficiently stopped by the above described action 15 a cent metres-t caresses} receiv d by e produced through thfffdiode r"v ofc'ondenser oandresisto'r M; as pieviously"cle-- scribed, then such remaining portions of the transient signals are effectively blocked from reaching the grid A of tube 5| b y'the action just discussed. amplified in the triode section of tube, so'that the remaining portions of the receiver systei'n' are actuated solely :by' the wanted signals, and are not afie'cte'd'b'y any unwanted signals;

It is Well-known inch-e aft that when a Coll denser isodnnected in multiple with a resistor, such as resistor M and condenser 0,, or resistor C and condenser N, etc., any currents flowing through the combination. will flow' principally through the condenser until it be fully charged,

and that all the current will flow through the re 7 sistorffafter the" condenser has been charged. Thus such a; condenser"and resistor will con-' stitute a delay circuit, and the period of delay will be determined by the relative values o'f'the two components. In like fashion, as is well known in the art, when a potential is removed froni'su'ch paralleled resistor and condenser, the condenser will discharge through the" resistor, the time of the discharge being a joint function of the capacitance,'the potential, and the resist ance. employed. Thus such a combination will provide" a delayjc'ir'cuit au'tdxziatica'lly self-releasing. If the'compcnent parts are prep:

erly'fchosen, as is conte plated here wanted signals are of such duratio sired potentials ar'e estabnshea across'tfi tor similarly, transient signals, which a erally of much shorter duration than the signals (or can bemacie so here n), do notpers'ist for a sufficient time to establish undesired potentials across the resistors, :biitoh' theses-nary dissipate uremsel es n parn'au char ing the c'ondf'enser's' an leaking as: through resistors.

(0) A' third effect of the" signal received by tube 5| from tube 47 is to amplify the w nt'e'd' signal received by in ert: A froin the rec ifier circ as illstds cribed,

' in -menswear mum-g eye t be seen? "mate-s the neces'sity of tuniri'e rece v r trimmers with meters. These trimmers are 's'hown'as' facijustable in Fig. 2. Meters are bulky, quite delicate and expensive. Tube 53 is light, fairly rugged andcomparatively inexpensive. It is more than satisfactory as a meter replacement for" the danger of burning out is substantially nated and it then is always available forus peaking the receiver to frequency, 4

Reference will now be had to Figs. 3 and 4 Wherein th'e stepper is" illustrated and the signal operated system is also illustrated. V H erein the twelve pole plug 63 is" associated with the twelve pole socket 40 of Fig. 2. 62 indicates the" primary of the power transformer'having second aries 63 to 69 inclusive. Across series windings 65 and 65 isthe' r'ectifier TD maybe of seleniuni type.

w Herein there is provided an alternating cur-f rent pulse relay 11, a stepper" ecu-structure 2, a timing relay i3 and a release latch relay (4. In addition there are nine switches, see Fig. 3,

as shown, two of which are of difierential three The impressed signal is applied to the stepper power which advances stepper arm 15 over the several contacts (24 being illustrated), each of which is connected by its individual connection Such signals are, accordingly, not

18 to an individual selection mechanism not shown I 4 In general, the operation'ofthe stepper mech anism broadly is that disclosed in. said patent, wherefore it is believed no further detailed description of that illustrated herein is believed This negative Voltage is on. steady during the sending of the wanted signals.

The present system also developes a negative voltage similar to an A. V. C. voltage. Herein the radio frequency signal is not continuous as in the patented system. Therefore, the pres- ,ent invention provides for protection against transients between pulses of the radio frequency signal.

Specifically the interstage transformer, having primary, 48 and secondaries 49 and 59, see Fig. 2, by such separation, accomplishes the two fold purpose of actuating relay 55 in the limited time available for actuation and rendering the amplifier reasonably less sensitive during the sequence of pulses, jv j In detail secondary 50 developes a negative voltage when the receiving system is supplied with energy, whichvoltage is applied to amplifier tube 4'! for the purpose of rendering it less sensitive, especially to extraneous transients during a sequence of pulses. Thus a squelch'action results.

Secondary 49, it 'Will be noted, is not tuned. This makes it faster in operation. Secondary 49 isused to develope a D. C. voltage which voltage is .used to operate the D. C. amplifier of which the triode 5| is a part. This causes tube 52 to conduct each time a radio frequency pulse is sent. I

While the invention has been illustrated and described in'great detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character. X I

The several modifications described herein as well as others which will readily suggest themselves to persons skilled in this art, all are considered to be within the broad scope of the in-.- vention, reference being had to the appended claims.

The invention claimed is:

1. In a remote signaling system of selective type wherein power lines supply alternating current power to ,a transmitter, a receiver and a stepper; the lines servin as signal channels and the transmitter applying selected signals of pulsed high frequency type to the receiver for predetermined actuation of the stepper in accordance with the selected pulsed signal, the combination of means normally preventing receiver actuation by line transients while the receiver is standing by and conditioned to pass wanted signals, and a second means normally preventing distortion by line transients of wanted signals and including a circuit for applying negative voltage to the controlled grid of the amplifier tube of the receiver, the negative voltage being effective at all times the receiver is operative, the receiver including an interstage radio frequency transformer with separate secbndaries, and a duplex diode-triode tube connected thereto for the purpose described.

2. In combination a receiver having an electri cal unit responsive to signal impulses received by the receiver, said unit comprising at least three interconnected sections, a time-delay device operatively associated with the second of the said sections for limiting the response of the first of said sections to responses greater than a predeter-' mined duration, a second time-delay device operatively associated with said second section'for limiting the response of the third section to responses of greater than a predetermined duration, said two time-delay devices simultaneously effecting such limiting action, although not necessarily in the same degree, and a separate auto- FRED H. OSBORNE. JOHN H. RIGGS.

REFERENCES CITED The following references are of record in' the file, of, this patent: I

UNITED, STATES PATENTS Number Name Date 1,763,390 Davis June 10, 1930 2,135,571 7 Foster Nov. 8, 1938 2,154,311 Levy Apr. 11, 1939 2,229,097 Koenig Jan. 21, 1941 2,258,654 Koenig Oct. 14, 1941 2,264,764 Koerner Dec. 2, 1941 2,307,771 Denton Jan. 12, 1943 2,333,992 Fox Nov. 9, 1943 2,343,115 Noble Feb. 29, 1944 2,346,238 Schmidt Apr. 11, 1944 2,348,312 Schmidt May 9, 1944 2,357,237 Thompson Aug. 29, 1944 2,379,799 Haigis July 3, 1945 2,387,144 Hayslett Oct. 23, 1945 2,490,238

Simons Dec. 6, 1949, 

